Jambs adams



J. ADAMS.

Hydrometer.

Patented Jan. 15. 1861.

\L r L )4 f I!!! nvnzor' UNITED STATES PATENT OFFICE.

JAMES ADAMS, OF NEW YORK, N. Y.

HYDROMETER.

Specification of Letters Patent No. 31,100, dated January 15, 1861.

To all whom it may concern:

Be it known that I, JAMEs ADAMs, of the city, county, and State of NewYork, have invented a new and useful Improvement in Hydrometers,Saccharometers, and other Instruments for Ascertaining the SpecificGravity of Liquids; and I do hereby' declare that the following is afull, clear, and exact description of the same, reference being had tothe accompanying drawing, forming part of this specification, saiddrawing representing a side view, partly in section, of a hydrometerconstructed according to my invention. 7

My invention consistsin the construction of a hydrometer or otherinstrument for ascertaining the specific gravity of liquids with'itsbulb and lower part of hard vulcanized india-rubber, gutta-percha, oranalogous substances, and its stem of silver or other metal by whichconstruction the instrument is made to possess advantages over one madewholly of metal or one made wholly of india-rubber or gutta-percha,inasmuch as the bulb is less liable to have its form changed by beingcarelessly laid or thrown down or let fall, than the metal bulb, and thestem is capable of finer and more accurate graduation and less liable tohave its graduations defaced and less liable to be bent than the indiarubber or gutta percha stem.

A, represents the principal bulb of the hydrometer; B, the lower stem;and O, the lower bulb containing or constituting the weight; all made ofhard vulcanized indiarubber or gutta-percha and made of one or morepieces.

D, is the graduated upper stem made of silver or other metal tubing andattached to the bulb A, in any suitable manner. The drawing representsthis attachment as being made by a shouldered metal plug a, solderedinto the metal tube and screwed into the top of the bulb, but a similarplug of the same material as the bulb may be used such plug beingcemented into the tube and screwed into the bulb; or the tube may bescrewed into the bulb without the use of a plug. The metal stem D, isgraduated by engraving in the usual manner and its lines of graduationso far from being obliterated.

by handling with dirty hands or use in dark colored liquids is onlyrendered plainer; but an india-rubber stem being of dark color andhaving its lines of graduation filled with white lead to make themvisible is liable to have the lines obliterated by dirt, be-

sides which it is very liable to be warped 'if laid away carelessly whenwarm, which is not the case with the metal stem.

That I claim as my invention and desir to secure by Letters Patent is-The construction of a hydrometer or other instrument for ascertainingthe specific gravity of liquids substantially as herein described bycombining with its bulb and lower part made of hard vulcanizedindia-rubber or gutta percha a graduated upper stem made of metal.

JAMES ADAMS.

Witnesses:

SALEM H. WALEs,

